This invention relates to a novel plant extract-containing beverage, and relates more detailedly to a beverage containing a flavonoid-containing plant extract selected from the group consisting of ginkgo (Ginkgo biloba) leaf extract, persimmon leaf extract, crataegus extract, Japanese pagoda (Sophora japonica) extract and lycium fruit extract.
Flavonoid-containing plant extracts such as ginkgo leaf extract, persimmon leaf extract, crataegus extract, Japanese pagoda extract and lycium fruit extract have been utilized from long ago as a herb crude drug. Thus various beverages to which they are added are expected to become healthy beverages. However, all the above flavonoids are liable to form turbidity and precipitates are formed by long-term preservation, and thus a countermeasure is necessary for stability enhancement. Heretofore, there have been carried out as countermeasures for the prevention of turbidity and precipitation in such beverages 1 centrifugation treatment, 2 filtration treatment, 3 enzymatic treatment 4 compulsory precipitation with a coagulant, 5 heightening of the viscosity of products, etc., and actually these means are combined in many cases.
However, even if a precipitate immediately after the preparation can be removed by centrifugation, secondary turbidity and precipitation occuring during preservation cannot be prevented. Further in case of the filtration treatment, secondary precipitation cannot be prevented by filtration accuracy in a degree such that only an initial precipitate is removed. When accurate filtration such as ultrafiltration using an ultrafilter is carried out, the formation of a secondary precipitate is fairly reduced, but at the same time there arises a problem that effective components are removed, too. The enzymatic treatment and the compulsory precipitation treatment with a coagulant take many costs on chemicals to be used such as the enzyme or coagulant, the treatments take a long time, and thus the costs are expensive and moreover the loss of the effective ingredients is large.
By the method to heighten the viscosity of products, precipitation may be prevented but turbidity is difficult to prevent, and moreover, in case of plant extract-containing beverages, refreshing feeling is spoiled and the heightening of the viscosity becomes a strong minus factor for functional aspects.